package cn.idu.javanote.a509;

public class Main {
    public static void main(String[] args) {

        System.out.println(fib(30));
    }

    public static int fib(int N) {
        if (N == 0 || N == 1) return N;
        return fib(N - 1) + fib(N - 2);
    }
}
